The Effect And Mechanism Of ApoA-â…  Mimetic Peptide ELK-2A2K2E On Inflammation In Macrophage

Objective: The aim of this study was to determine whether the apoA-1mimeticpeptide ELK-2A2K2E regulates the expression of inflammatory cytokines whenit was combined with ABCA1and made the activation of JAK2-STAT3signalingpathway,Methods: THP-1cells treated by PMA were induced into macrophages, which weredifferentiated macrophage foam cells by ox-LDL. The levels of the cytokine weremeasured by enzyme-linked immunosorbent assay (ELISA)after THP-1cells weretreated with the apoA-1mimetic peptide ELK-2A2K2E at different concentrations orincubated with ELK-2A2K2E (40μg/ml) for increasing periods of time(0,6,12,24h)，then exposed to LPS. THP-1macrophage-derived foam cells were treated withELK-2A2K2E or nothing, then exposed to LPS and actinomycin D(act D) to inhibittranscription. TNF-α、IL-6and MCP-1mRNA levels at different time points(0,30,60, and120min) were quantified using real-time quantitative PCR. Our experimentalso usedABCA1, STAT3, TTP siRNA or JAK2inhibitor to incubate together withELK-2A2K2E. The protein levels of activity ABCA1、P-JAK2、P-STAT3、TTP、TNF-α、IL-6and MCP-1were examined.Results: The important found was that TNF-α、IL-6and MCP-1protein levels werealso suppressed by ELK-2A2K2E in a time-and dose-dependent. MeanwhileELK-2A2K2E increased corresponding mRNA destabilization. Further studiesshowed that ELK-2A2K2E increased mRNA decay via JAK2-STAT3signalingpathways through ABCA1increasing TTP; However, after THP-1macrophages were treated with ABCA1, STAT3, TTP siRNA or JAK2,inhibitors treatment, TNF-α、IL-6and MCP-1protein levels were increased.Conclusions:1. ApoA-I mimetic peptide ELK-2A2K2E increases TNF-α、IL-6andMCP-1mRNA decay， then reduces their protein levels2. ApoA-I mimic peptide ELK-2A2K2E combined with ABCA1, the activation ofJAK2-STAT3signaling pathway, promotes the expression of TTP, increases TNF-α、IL-6and MCP-1mRNA decay, reduce the expression of the correspondingprotein.